Schrader, F.C., 1900, Preliminary report on a reconnaissance along the Chandlar and Koyukuk Rivers, Alaska, in 1899, in Walcott, C.D., Twenty-first annual report of the director of the United States Geological Survey, 1899-1900: Part II - General geology, economic geology, Alaska: U.S. Geological Survey Annual Report 21-II, p. 393-440.